body {
  padding-left: 8em;
  padding-right: 8em;
}
table {
  padding-left: 2em;
  padding-right: 2em;
  box-align: center;
}
h1 {
  text-align: center;
  font-size: 32px;
}
h2 {
  font-size: 22px;
  counter-increment: h2counter;
}
h2:before {
  content: counter(h2counter, cjk-ideographic) '\3001';
}
.filling20 {
  border-bottom: 1px solid #333;
  color: #fff;
  display: inline-block;
  width: 20em;
  position: relative;
  text-align: center;
}
.filling10 {
  border-bottom: 1px solid #333;
  color: #fff;
  display: inline-block;
  width: 10em;
  position: relative;
  text-align: center;
}
.filling {
  border-bottom: 1px solid #333;
  color: #fff;
  display: inline-block;
  width: 6em;
  position: relative;
  text-align: center;
}
.filling:hover {
  color: #008000;
}
.yes_no {
  color: #fff;
  display: inline-block;
  width: 2em;
  position: relative;
  text-align: center;
}
.yes_no:hover {
  color: #008000;
}
.parenthesis {
  float: right;
  margin-right: 5em;
}
.parenthesis:before {
  content: '(';
}
.parenthesis:after {
  content: ')';
}
.choice {
  color: #fff;
  display: inline-block;
  width: 4em;
  position: relative;
  text-align: center;
}
.choice:hover {
  color: #008000;
}
xmp.code {
  border: 1px solid;
}
li {
  margin-top: 2px;
}
.solve {
  color: #d3d3d3;
}
.solve:before {
  font-weight: bold;
  content: '答:';
  display: block;
}
